{
    "mode": "info",
    "parameter": "envsubst",
    "section": "",
    "url": "https://www.chedong.com/phpMan.php/info/envsubst/json",
    "generated": "2026-11-15T14:56:52Z",
    "sections": {
        "File: gettext.info,  Node: envsubst Invocation,  Next: evalgettext Invocation,  Prev: ngettext Invocation,  Up: sh": {
            "content": "15.5.12.5 Invoking the 'envsubst' program\n.........................................\n\nenvsubst [OPTION] [SHELL-FORMAT]\n\nThe 'envsubst' program substitutes the values of environment\nvariables.\n\n*Operation mode*\n\n'-v'\n'--variables'\nOutput the variables occurring in SHELL-FORMAT.\n\n*Informative output*\n\n'-h'\n'--help'\nDisplay this help and exit.\n\n'-V'\n'--version'\nOutput version information and exit.\n\nIn normal operation mode, standard input is copied to standard\noutput, with references to environment variables of the form '$VARIABLE'\nor '${VARIABLE}' being replaced with the corresponding values.  If a\nSHELL-FORMAT is given, only those environment variables that are\nreferenced in SHELL-FORMAT are substituted; otherwise all environment\nvariables references occurring in standard input are substituted.\n\nThese substitutions are a subset of the substitutions that a shell\nperforms on unquoted and double-quoted strings.  Other kinds of\nsubstitutions done by a shell, such as '${VARIABLE-DEFAULT}' or\n'$(COMMAND-LIST)' or '`COMMAND-LIST`', are not performed by the\n'envsubst' program, due to security reasons.\n\nWhen '--variables' is used, standard input is ignored, and the output\nconsists of the environment variables that are referenced in\nSHELL-FORMAT, one per line.\n",
            "subsections": []
        }
    },
    "flags": [],
    "examples": [],
    "see_also": []
}